1. Field of the Invention
The present invention relates to a multi-receiving demodulator, and more particularly, to a multi-receiving demodulator for receiving broadcast signals from all over the world.
2. Description of the Related Art
Many different TV broadcasting systems exist in the world. That is, there are M, I, B/G, D/K, and L systems for both VHF and UHF transmission systems. Multi-receiving systems have been developed to receive signals from these TV systems. However, the L system employed in Europe has a VHF channel bandwidth of 7 MHz and a UHF channel bandwidth of 8 MHz. For the L system, vestigial side-band (VSB) positive modulation is used as a video modulation method, and amplitude modulation (AM) is used as an audio modulation method. Furthermore, a VHF low channel (hereinafter, referred to as L') and a VHF high channel and UHF channel (hereinafter, referred to as L) should be differently constituted in the L system, as compared to other systems M, I, B/G, and D/K, because the former and the latter perform different heterodyning. Therefore, the receiver in a multi-system TV often excludes the L system to avoid the necessary complicated demodulation circuitry, and thus has difficulty in receiving TV broadcast signals from countries or areas adopting the L system.